Fluorescent tube socket



Patented Mar. 7, 1950 UNITED STATES PATENT OFFICE FLUORESCENT TUBE SOCKET Benjamin ThomasJoi-dan, Molena, Ga., assigner of one-half ton, Ga.

to ,AbrahamG Singleton, Thomas- Application'Juvly 6, 1945, Serial No. 603,539

The present invention relates to sockets ,such

as are especially, but not necessarily, adapted for supporting and supplying current to ,jsppposite' Brieiiy, the preferred type of sockehjherein under consideration is characterized by n elongated body of general rectangular form, ihis having a curved outer end forming a portig'nof theperimeter and the latter being provided with spaced parallel slots to permit easy insertion and removal of the tube prongs. The body is formed with an internal cavity and in this cavity is provided mechanism including resilient contact fingers, the latter being constructed to ,constitute detents, the prongs of the tube coacting; with the detents, and spring-pressed means being provided to force the prongs into satisfactorylelectrical contact with said detents.

In carrying out the principles of the invention, I adopt and use a contact-equipped body of the aforementioned type and provide therein a reciprocatory pin or plunger which constitutes an available operating member, and this" is forced out by a spring and held in a normal position and is provided with a novel retainer which presses the prongs of the tube against the terminals forming the detents on the contact fingers.

Other objects, features and advantagesof the invention will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are` employed to designate like parts throughout thel views: A

p Figure l is an elevational view showing a fragmentary end portion of a conventional prongequipped fluorescent tube and illustrating how it is mounted in the improved safety-type socket.

Figure 2 is an inside elevational view of the socket, that is, a view of the same seen in Figure 1 observing it in a direction from right to left.

' Figure 3 is a section through th"'socket, this being on the plane of the line 3- 3"'of Figure 1.

Figure 4 is a view like Figure '3 showing the prongs heldin place and locked against accidental displacement.

Figure 5 is also a view like Figure .3 (the latter ready forV the tube change.

'.Figure 6 is a central longitudinal sectional s claims. (C1. 173-328) I yview showing a modified form of the invention with the parts closed and the socket empty Figure 7 is a view like Figure 6, but showing the prongs of the tube fastened in place.

Referring now to the drawings by distinguishing reference numerals, the socket comprises a unitary body of appropriate material and dimensions, the same being suitably enlarged at one end, as indicated at I0, and of elongated form, this being the body, as at I I. The marginal portion of this is such that the outer end is rounded or of arcuate form, as at I2. This forms the aforementioned crown. In the inner side I provide spaced parallel slots I3 for insertible and removable accommodation of the conventional prongs I4 on the regular or standard fluorescent tube I 5. On the interior is a cavity I6 to accommodate the contact and retaining elements. At the enlarged end IU of the structure are outer lugs I1 between which is a central lug I8, the latter being fashioned into a guide, this by way of the bore I8a or slot, which extends therethrough. On opposite sides of this guide I provide inlets for the limbs I9 of the duplicate current-conducting and contact ngers. The outer ends of these are bent laterally, as at 20, and fastened projects beyond the crown I2 and is provided with a suitable actuating knob or head 28. A substantially conical follower 21 is fastened by a pin 28, or otherwise mounted, on the shank of the-plunger, and this follower is fashioned into a cup,as at 29 (see Fig. 5), said cup fitting down snugly over the adjacent end portion of the guide 24. There is a spring 30 on the shank of the plunger surrounding same and interposed between the follower 21 andthe guide Ia. Thus,

" it will be seen that in Figure 3. .we see the socket closed and empty. In Figure 5, we see the same socket open and empty, this ready Afor tube change. In Figure 4, we see the socket loaded or charged, that is, with the prongs I4 in place and the tube ready for use. By pressing in on the plunger head, 26 the follower, which is substantially conical, thenl becomes ang; expander and pressesv against the lateral bends 2:3 and spreads;- the contact ngers;apart,. as..shown-in Figure 5.`

shown in Figure 4.. Here it directly engages the.`

prongs I4 and forces them into form contact with the V-shaped detents 22.

In the form of the invention just described, the

plunger is of the push type, that is", the typel in` which the head 26 is pushed inin orderto ref lease the ngers by way of the. expander 21.. Inv Figures 6 and '7, a slight modication, based on the same principle of construction, is shown, and this is of the :so-called pull type. It is suilcient, therefore, to say that the plungerl 3l has a protruding end projecting beyond the slots 32 and adjacent crown portion 33. The numeral 34 designates ng-.ergrips to conveniently permit the' user to catch hold of same and to pull the pin` out from the guide. socket 35 in the main body. It will be noticed in this connection that the expander is in theform of' a tapered'collar 36 secured by a pin 31, said expander collaroperating between the converging cam portions 38 of the contact. iingers 39, Th'econtact fingers hereterminate on opposite sides-of the" guide 40inV`- shaped detent heads 4I to engage the prongs as shown in Figure 7. In this case, a coiled spring surroundsthek plunger pin, as at 42, and presses at one end against'the. expander collar 3E and at its opposite end against the flanged cup or re'- tainer 43. rDhe rim or flange of the cup iits over the guide dil th'esame as shown in the push type inv Figure 3. However, the cup 43 is freely slidable on the stern-or shank of the plunger andis held in placesolely by the spring. By catching hold of the grips 3d and pulling the plunger 3| out against the tension` of the spring, the collar 36 engages the cam portion 38 and expands the fingers to permit easy insertion and removal of` the` lamp prongs. Once the prongs'are in place, as shown in Figure 7; the spring acts on the-retainer 43 to force it against the prongs 14a and to hold the prongs securely against the-detents 4 l.

considered the introductory aims' and objects, here are additional factors worthy ofV attention. The following are considered advantages derived from the construction herein shown and described, to Wit:

1. To mechanically lock the prongs of the lamp tube in the socket in conjunctionwith the socket contacts to prevent'the'lamps from falling out of sockets dueto excessive vibration.

'2.'A means incorporated in; the- 'socketY and made a 'p'a'rtthereof to yrelease contacts fromthe'- lamp tube prongs.

' 3. Better electricaly contact is maintained due tothe springtension ofthe looking mechanism "which bears at all times on thel'amp tube prongs.

Tubular la-mpsmay beY inserted into the socket through straight `openings which eliminates the necessity'of revolving the lamp tubein order. toloclaa's isnecessaryin most of -the'present sockets now ontheifmarlret.

' 5. With theimproved socketit'fcan be made'` more substantial andrgives better electrical conk tact and lessr trouble.thanipresent-.sockets on the market.

multiple story buildings. The light tubes falling could result in a serious accident, or injury to products and machinery. Also where excessive vibration exists quite a bit of trouble is experienced with the present type sockets due to them becoming loose and not making the proper electrical contact and results in the lamps not burning and excessive maintenance cost.

Changes in shape, size, materials and rearrangement of details and parts may be resorted to in actual practice, so long as they do not depart' from' the-spirit of the invention or the scope of the attending claims, this as is well understood,

lclaim; v v. 1. A fluorescent .tube-accommodation socket of the class described vcomprising a body having an internalslotted chamber for reception of prongs on.a conventional-type fluorescent tube, a pair of duplicate companion contact fingers anchored at. Corresponding 21.11.18. 11i. Seid .body and. ,Projecting for use in tosaid ohamber ,*th e opposite ends of'said ngers being 4free and being provided with' substantially V-shaped detents and said detents being adapied` to releasably engage said prongs, a manually operable plunger slidably mounted insaid body fory operation vin said chamber, one end ofsaid plunger extending beyond the adjacent end of said casing, foracoessible operations, a coiled spring surroundingl the plunger, a prong clampingretainer.mounted forv operation on said plunger, said coiled. spring being engageable at one end withsaid retainerandat its opposite end with saidbOdy, said retainer being of cup-like form with the annular lip portionof the cup adapted to engage the prongs to hold the prongs against said detents,.in. the manner. and for the purposes described.

2. A socket of. theclass described comprising an elongated body providedV with. an internal cavity and a. pair. of. spaced parallel prong-accommodation and keeper notches opening. .into said cavity, guidesformed inthe body and eX- tending into thecavity., a plungerV mounted vfor reciprocation insaidguides and spanning said cavity, one end of said plunger projecting beyond the corresponding end. of said .body to render same readily accessible yfor convenient operation, av coiled .spring in-said cavity surrounding a portion of said plunger and bearing. at one end against said body, a. substantially truste-conical cup-like member fastened onthe plunger, the remaining end of said,springbearingagainst said member, apair. of spaced substantially parallel contact fingers mounted for operation in the cavityandsupportedin, said body, said ngers being disposed on ,oppositesides of theplunger4 as well as on diametrically opposite sides of Asaid frusto-.conical member-7 the freeterminals of. the ngers. being .of V-shaped ,form, ,said member functioning both as .aI detent for ,said prongs, and an expander for said fingers, andthe intermediate portions of said Contact iingers having oiset portionsdening camsvvithwhich said expander coacts...v v

.8. Afluorescent tubeaccommodation and supporting socket comprising abodyhaving an .in ternal cavity deiningI a'chamber, said chamber ger projecting'beyondthe corresponding end of said bodyforconvenience of accessible operation,

said bodyjalso'- having ;-a. pair-of spaced parallel. prong reception notches,=. saidnotchesopeningl4 ntosaid .chamberinsucna Amanner aszto .permit the prongs to enter the chamber by way of said notches, a substantially {fusto-conical member fastened on that portion of the plunger which is operable in said chamber, a coiled spring surrounding a portion of the plunger within the connes of said chamber, said coiled spring bearing at one of its ends against a coacting portion of said body and bearing at its opposite end against said frusta-conical member, and a pair of substantially parallel contact fingers mounted for operation in the chamber and anchored at corresponding ends in said body, said fingers being disposed on opposite sides of the plunger and also on diametrically opposite sides of said frustoconical member, the remaining ends of said ngers being free and of V-shaped form, said frusto-conical member functioning both as a detent for said prongs when the latter are engaged in said V-shaped terminals and as an expander for said fingers, the intermediate portions of REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,387,814 Ten Bosch Aug. 16, 1921 2,259,096 Alden Oct. 14, 1941 2,282,875 Mueller May 12, 1942 2,339,751 Beal Jan. 25, 1944 

